Vacuum delay valve

ABSTRACT

A vaccum valve connected in the vacuum line between the carburetor of an internal combustion engine and the servo vacuum motor controlling the spark advance in the distributor, contains a time-metering orifice delaying the application of vacuum to the spark advance actuator of the distributor for retarding the ignition timing during transient engine operation. Special filters are psoitioned on either side of the time-metering orifice for removing particulates from the fluid therebykeeping the valve free from contaminants that would plug the orifice. In addition, a thermal responsive actuator is used for controlling the valve operating according to the ambient temperature of the valve.

United States Patent 1191 I 1 Martin et a1.

VACUUM DELAY VALVE Ludwig 123/117 A [54] 3,729,132 4/1973 5] In nt sFrank J Martin; R. Holbmok, I 3,730,154 5/1973 Vartaman -l23/l 17 A bothof Ann Arbor Mich Primary Examiner-Manuel A. Antonakas [73] Assignee:-Chrysler Corporation, Highland tant xamine -Ronald B- CO Park, Mich.Attorney, Agent, or Firm-Talburtt & Baldwin [21] App]. N0.: 311,090 Avaccum' valve connected in the vacuum line between the carburetor of aninternal combustion engine 521 U.S. c1.... 123/117 A 137/496 251/117 1and vacuum spark/ad g 251/205 vance in the distributor, contains atime-metering ori-. 51 1m. (:1. F02p 5/04 fice delaying the aPP'iCmimvacuum the Spark [58] Field of Search 123/117 251/117 advance actuatorof the distributor for retarding the ignition timing during transientengine operation. Special fil ters are positionedon either side of thetime- [56] References'cited metering orifice for removing particulatesfrom the fluid thereby keeping the valve free from contaminants UNITEDSTATES PATENTS that would plug the orifice. In addition, a thermal re-Marshall A sponsive actuator is used controlling the valve op- H giggerating according to the'ambient temperature of the 316991936 10/1972Vartanian..' 1.1. 123/117 A valve" 3,712,279 l/l973 Vartanian 123/1 17 A5 Claims, 8 Drawing Figures a 4 7 id 1. Field of Invention Thisinvention relates to vacuum valves in general I and, particularly totime delay metering valves as used for controlling exhaust gascombustion engine.

2. Prior Art Various systems have been and are used for controlling theengine vacuum spark advance control motor for reducing exhaustemissions. One such system, identified as atransmission spark advancecontrol system, utilizes a fluid pressure responsive switch forelectrically disabling the spark advance control below a certain vehiclespeed if the vehicle is equipped with an automatic transmission. If thevehicle is equipped with a manual transmission, the vacuum advance isdisabled when the transmission is in first or second gear. An example ofsuch a switch is found in US. Pat. No. 3,600,535.

Another system is identified as an automatic vacuum spark advancecontrol system and is an electric controlled vacuum and speed responsivesystem for disabling the engine vacuum advance during acceleration belowcertain speeds and within a predetermined vacuum range. Anexample of acontroller as used in such a system is found in US. Pat. No. 3,665,904.

SUMMARY OF INVENTION emissions from an internal is reduced.

a valve It is still ahother object of this invention to filter out thesmallest particles in the vacuum fluid without restricting the fluidflow through the valve.

It is yet another object of this invention to control the operation'ofthe valve in response to the temperature environment of the valve. I i

These and other objects of the invention will become apparent in thefollowing drawings, detailed description and claims of a vacuum delayvalve having a housing containing a chamber therein with an input andoutput port for fluid communication with the chamber. A plate issupported within the chamber between the input and. output ports fordividing the chamber into two vacuum-tight chambers. Located through theplate and in fluid communication with both chambers is a unidirectionalvalve for allowing the vacuum at the output portto be reducedsynchronously with the vacuum at the input port. Positioned adjacent tothe unidirectional valve on theplate and in fluid communication betweenboth chambers is a timemetering delay orifice for controlling the rateof change of the vacuum at the outut port when the vacuum at the inputport is increased. In addition, a thermal responsive actuator cooperateswith the unidirectional valve, to change the valve characteristics to'abidirectional full flow valve below a predetermined temperature range.

DESCRIPTION OF THE DRAWINGS the filter .valve in FIG. 2;

FIG. 7 is a plan view of another embodiment of the time metering orificeof the valve; and

FIG. 8 is a sectional view taken along line 88 of FIG. 7. t

DETAILED DESCRIPTION Referring to the figures by the characters ofreference, there is illustrated in FIG. 1 a schematic of an internalcombustion engine spark advance control system utilizing a vacuum delayvalve. The vacuum delay valve 10 is interconnected in the vacuum line 12and 13 between the ported vacuum port 14 of the carburetor l6 and vacuummotor 18in the spark advance mechanism of the distributor 20. The vacuumvalve 10 controls the application ofvacuum to the vacuum motor 18 foradvancing'or retarding the ignition of the engine 22.

The vacuum valve 10 comprises a housing 24 having an enclosed chamberwith at least two ports .26 and 27 with an integral nipple extension forfluid communication therewith. One of the ports 26 is connected by afirst vacuum line 12 to the carburetor 16 and another port 27 isconnected by a second vacuum line. 13 to the vacuum motor 18 in thespark advance control unit.

In the carburetor '16, schematically illustrated in FIG. 1, the throttleplate 28 is in the illustrated position when the internal combustionengine 22 is at idle. The

valve of the ported vacuum at this time isyapproximately equal to theatmospheric pressure of the air being drawin into the carburetor 16 fromthe air cleaner 30. As the throttle is opened, the throttle plate 28'moves in a counter-clockwise position, the ported vacuum approaches thevalue of the manifold vacuum. In systems without the vacuum valve 10,ported vacuum is supplied directly 'to the spark advance control vacuummotor 18 for controlling the ignition point of the engine 22. Duringtransient'vehicle operation, the spark is advanced and, as a result, theemission gases are rich in oxides of nitrogen. It is a function of thevacuum delay valve 10 to delay the vacuum build-up'applied to the sparkadvance control vacuum motor during transient engine operation therebyeffectively retarding the spark.

As previously stated, the vacuum valve 10 comprises a housing 24containing an enclosed chamber with at least two spaced-apart ports 26and-27, namely, an input 26 and output 27 port. Supported within thechamber is a plate means 32 for dividing the chamber into a first 34 anda second 36 pressure chamber wherein each of said chambers has a portconnected thereto. I

In the preferred embodiment, the plate 32 has an aperture 38 therein forreceiving a unidirectional or dump valve 40 for controlling the fluidcommunication between the two chambers 34 and 36. When the pressure inthe first chamber 34 is greater than the pressure in the second chamber36, the dump valve 40 permits unrestricted fluid communication betweenthe chambers.

However, when the pressure is less or the vacuum greater in the firstchamber, the dump valve blocks fluid communication between the twochambers.

Located in the plate 32 and out of the confines of the dump valve 40 isa delay orifice 42 for controlling the rate of fluid communicationbetween the chambers when the vacuum is greater in the first chamber 34.Therefore, the dump valve 40 allows unrestricted fluid communicationbetween the chambers when the pressure is greater in the first chamberand the delay orifice 42 controlsv the fluid communication between thechambers when the vacuum is greater in the first chamber 34.

In the preferred embodiment and as illustrated in FIG. 1, the vacuumvalve is physically positioned on either side of the engine compartmentfire wall'44 with a portion of the valve protruding into the cowl inletarea. Located in the portion of valve in the cowl area is a thermalactuating member 46 or bi-metal which cooperates with an aperture 48 inthe dump valve making the operation of the dump valve responsive to thetemperature of the valve environment.

As illustrated in FIG. 3, the dump valve 40 is an umbrella-shaped valvehaving the axially located aperture 48 extending through both theumbrella portion 50 and stem portion 52 of the valve. The stem portion52 is located in the aperture 38 in the plate 32 between the chambers34- and 36 thereby locating and holding the valve in position. Theaperture 48 provides bidirectional fluid communication between thechambers.

When the temperature of the environment surrounding the valve is above afirst predetermined temperature which is 68F., the bi-metal member 46 isin its first position in contact with the stem portion 52 of the dumpvalve thereby sealing the aperture 48 against fluid communicationtherethrough-When the temperature goes below a second predeterminedtemperature of 48F., the bi-metal member 46 snaps over to its secondposition away from the dump valve thereby opening the aperture 48.

The aperture 38 in the plate 32 in the preferred embodiment asillustrated in FIG. 5, comprises an elongated slot having a portion 54at one end with a diameter which is greater than the diameter of thestem portion 52 of the dump valve. At the other end of the slot there isthe aperture 38 having a vdiameter adapted to receive one of the smallerdiameters of the stem 52. The particular configuration of the slot asillustrated in FIG. permits easy insertion of the valve 40 into theplate 32 at the one end and also provides a path for fluid communicationbetween the chambers when the pressure is greater in the first chamber.Thus, if the temperature is greater than 68F, the dump valve functionsas a unidirectional valve inasmuch as the axially located aperture 48 isclosed by the thermal actuated member 46. Below 48F., the dump valve isa bi directional valve with fluid communication in both directionsthrough the aperture 48 in the valve.

The delay valve in a preferred embodiment is a small orifice 42extending through the plate 32 and located outside of the confines ofthe umbrella portion 50 of the dump valve 40. The orifice 42 has apredetermined diameter for controlling the rate of fluid communicationbetween the chambers 34 and 36 when the temperature is greater than 68F.and the dump valve aperture 48 is sealed.

In the preferred embodiment as illustrated in FIG. 6, the side 56 of theplate 32 facing the first chamber 34 has a coined or thinned area- 58for reducing the thickness of the plate 32. The orifice 42 is locatedwithin this area thereby reducing the length of the orifice and reducingthe manufacturing time to put the orifice in the plate,

In the preferred embodiment, the orifice 42 is .005 inch long and thediameter is 0.003 inch resulting in a time delay of 28 seconds forincreasing the vacuum in the second chamber 36 from O to 9.5 inches ofmercury when the vacuum in the first chamber 34 is equal to 12 inches ofmercury.

FIGS. 7 and 8 illustrate a modification of the delay valve comprising asecond aperture 60 in the plate located under the umbrella portion 50 ofthe valve and a small coined slot 62 extendingfrom the second apertureto outside the umbrella perimeter. The volume of the slot 62 enclosed bythe edge of the umbrella determines the time delay. The second aperture60 can also function as the check valve allowing communication when thevacuum is greater in the second chamber.

Positioned on either side of the orifice 42 in both chambers is a filter64 for filtering out foreign particles in the fluid passing through thevalve. Each of the filters 64 is a laminated filter comprising of fourlayers which are enclosed in a housing 66 forming a unitary structure.The first filter member 68 which is positioned furthest from theorifice, is a random orientated felt material providing a depth filterfor trapping relatively large foreign particles in the fluid flow andalso for dispersing the fluid flow through the filter. The second filtermember 70 which is positioned in contact with the first filter member 68is a paper filter for removing from the fluid passing through the firstfilter member, particles having a size greater than 15 microns. Thethird filter member 72 positioned in contact with the second filtermember is fiberglas filter for removing from the fluid passing throughthe second filter member, particles having a size greater than 0.3microns.

The last layer 74 of the filter 64 is a nylon screen for protecting thefiberglas filter 72 when the nylon housing 66 is moulded around thelaminated members forming a unitary structure. Thus, it is seen that thefluid leaving the filter 64 will be dispersed fluid free from particlesgreater than 0.3 microns in size. The filter 64 is pressed into thevalve housing 24 such that all fluid flow must go through the filters 64and cannot go around the filter housing. A spring clip 76 may be usedfor holding the filter in the housing.

In addition to the above two laminated filters 64, there is anadditional filter 78 in the first chamber. This filter is for removingfrom the fluid any liquids such as gasoline or water which may be in thevacuum line 12 coming from the carburetor and which, if not removed,would tend to clog and block the filter 64.

The method of fabricating the delay valve comprises the use of anelectric discharge machine for boring the orifice 42 in the plate 32.The plate 32 is first formed to size and shape as illustrated in FIG. 5having the central aperture 38 and 52 formed therein. Next, a small area58 near the outside periphery of the plate is coined to a reducedthickness. The plate member 32 is positioned within an electricdischarge boring machine in such a 'manner that the electron beam fromthe machine will pass through the coined area 58. As previouslyindicated in the preferred embodiment, the orifice 42 is 0.003 inch indiameter.

. After all the individual parts of the delay valve are fabricated, theyare subjected to an ultrasonic cleaning process to remove all foreignparticles. After cleaning thevalve is then assembled in a Clean Roomarea. This method of assembly'assures that when the valve 10 isassembled, there are no dirt particles withinthe valve which will renderthe valve inoperative. As previously mentioned, the laminated filters 64function to clean the fluid flow through the valve after the valve isassembled. The filters are such as to reject particles as small asl/200th the diameter of the human hair from reaching the orifice 42. I

As illustrated in the drawings, a major portion of the first chamber 32is offset from the second chamber 36 and, in order to provide fluidcommunications between the two chambers a rubber gasket 80 cooperatingwith an upper housing member 82 forms a passageway between both sectionsof the first chamber 34.

As indicated above, the function of the vacuum valve is to delay thevacuum build-up to the distributor vacuum 18 motor. This delay occurswhen the vacuum in the carburetor 16 is greater than the vacuum in thedistributor vacuum motor 18. This delay functions to retard the enginespark thereby delaying the burning process in the cylinders. When theburning process is delayed the exhaust, gas temperatures are increasedand peak cylinder pressures are reduced thereby reducing the amount ofunburned hydrocarbons and oxides of nitrogen in the exhaust gas from theengine 22. However, due to thestructure of the valve 10 when thetemperature is low below 48F there is'no delay through the valve ineither direction.

There .has thus been shown and described a vacuum delay valve 10 such asmay be used' in a motor vehicle. At predetermined temperatures, thevalve operates to delay the build-up of vacuum from the carburetor tothe vehicle spark advance control unit. However, when the vacuum isgreater at the control unit, the valve functions to providenonrestrictive fluid flow to reduce.

that vacuum.

What is claimed is:

I. A vacuum delay valve comprising:

a housing defining an enclosed chamber having at least two portstherein;

plate means having an aperture therein and supported within said chamberfor dividing said chamher into first and second separate pressurechambers each of which chambers has a port connected thereto for fluidcommunication therewith;

unidirectional valve means located within said aperture for sealing saidaperture from fluid communication between said chambers when the vacuumin the first chamber is greater than the vacuum in the second chamberand operable for conducting fluid communication between said chamberswhen the vacuum in second chamber is greater than the vacuum in thefirst chamber;

a delay valve means located in said plate means and controlling the rateof fluid communication between said chambers when-the vacuum in thefirst chamber is greater than the vacuum in the second chamber; and

filter means positioned between said plate means and each of said portsandcomprising:

a first filter memberfor dispersing the fluid flow therethrough andtrapping large elling in the fluid; I

a second filter member positioned for receiving the 5 fluid flow fromsaid first filter member for removing dirt particles larger than apredetermined size travelling in the fluid between said first member andsecond filter member;

a third filter member positioned for receiving the fluid flow from saidsecond filter member for removing dirt particles larger than apredetermined size travelling in the fluid between said second filtermember and the third filter member; and

a housing member for retaining said-first, second and third filtermembers in a unitary structure.

2. In the fluid flow valve according to claim 1 wherein the filter meansadditionally includes a fourth filter member for protecting said thirdfilter and a housing member for retaining said first, second; third andfourth filter members in a unitary structure.

3. In the fluid flow valve according to claim 2 wherein said firstfilter member comprises a random orientated felt material, said secondfilter member is a paper filter, said third filter member is. afiberglas filter and said fourth filter member is a nylon screen memher.

4. In a fluid flow valve according to claim 3 wherein said firstpredetermined size is' greater than microns and said secondpredetermined size isgreater than 0.3 microns.

5. In a motor vehicle with an internal combustion engine having avacuum-controlled distributor for controlling the timing point at whichthe engine is to ignite, a vacuum delay valve interconnected in thevacuum line between the carburetor and the vacuum motor controlling thedistributor, said vacuum valve comprising:

a pressure chamber connected at one end for fluid communication with thevacuum source in the carburetor and connected at the opposite end forfluid communication with the vacuum motor;

. plate means positioned within said pressure chamber for dividing saidchamber into two fluid-tight vacuum chambers;

a dump valve positioned within said plate means, said dump valve havingan aperture therein for interconnecting said two vacuum chambers;

atemperature responsive actuator for sealingsaid aperture at a firsttemperature allowing fluid flow between said vacuum. motor and saidcarburetor when the vacuum at the carburetor isless than at the motorand restricting fluid flow when the vacuum at the carburetor is greater;

an orifice delay valve positioned within said plate means forcontrolling the rate of the fluid flow between the vacuum motor and thecarburetor when the vacuum is greater at the carburetor;

laminated filter means positioned on either side of said plate means forremoving particles from. the fluid flowing between the vacuum motor andthe carburetor thereby maintaining said time delay valve free fromparticles; and j a gasoline filter means positioned in said pressurechamber between the carburetor and the laminated filter means forremoving gasoline from the fluid flowing through the valve.

dirt particles trav-

1. A vacuum delay valve comprising: a housing defining an enclosedchamber having at least two ports therein; plate means having anaperture therein and supported within said chamber for dividing saidchamber into first and second separate pressure chambers each of whichchambers has a port connected thereto for fluid communication therewith;unidirectional valve means located within said aperture for sealing saidaperture from fluid communication between said chambers when the vacuumin the first chamber is greater than the vacuum in the second chamberand operable for conducting fluid communication between said chamberswhen the vacuum in second chamber is greater than the vacuum in thefirst chamber; a delay valve means located in said plate means andcontrolling the rate of fluid communication between said chambers whenthe vacuum in the first chamber is greater than the vacuum in the secondchamber; and filter means positioned between said plate means and eachof said ports and comprising: a first filter member for dispersing thefluid flow therethrough and trapping large dirt particles travelling inthe fluid; a second filter member positioned for receiving the fluidflow from said first filter member for removing dirt particles largerthan a predetermined size travelling in the fluid between said firstmember and second filter member; a third filter member positioned forreceiving the fluid flow from said second filter member for removingdirt particles larger than a predetermined size travelling in the fluidbetween said second filter member and the third filter member; and ahousing member for retaining said first, second and third filter membersin a unitary structure.
 2. In the fluid flow valve according to claim 1wherein the filter means additionally includes a fourth filter memberfor protecting said third filter and a housing member for retaining saidfirst, second, third and fourth filter members in a unitary structure.3. In the fluid flow valve according to claim 2 wherein said firstfilter member comprises a random orientated felt material, said secondfilter member is a paper filter, said third filter member is a fiberglasfilter and said fourth filter member is a nylon screen member.
 4. In afluid flow valve according to claim 3 wherein said first predeterminedsize is greater than 15 microns and said second predetermined size isgreater than 0.3 microns.
 5. In a motor vehicle with an internalcombustion engine having a vacuum-controlled distributor for controllingthe timing point at which the engine is to ignite, a vacuum delay valveinterconnected in the vacuum line between the carburetor and the vacuummotor controlling the distributor, said vacuum valve comprising: apressure chamber connected at one end for fluid communication with thevacuum source in the carburetor and connected at the opposite end forfluid communication with the vacuum motor; plate means positioned withinsaid pressure chamber for dividing said chamber into two fluid-tightvacuum chambers; a dump valve positioned within said plate means, saiddump valve having an aperture therein for interconnecting said twovacuum chambers; a temperature responsive actuator for sealing saidaperture at a first temperature allowing fluid flow between said vacuummotor and said carburetor when the vacuum at the carburetor is less thanat the motor and restricting fluid flow when the vacuum at thecarburetor is greater; an orifice delay valve positioned within saidplate means for controlling the rate of the fluid flow between thevacuum motor and the carburetor when the vacuum is greater at thecarburetor; laminated filter means positioned on either side of saidplate means for removing particles from the fluid flowing between thevacuum motor and the carburetor thereby maintaining said time delayvalve free from particles; and a gasoline filter means positioned insaid pressure chamber between the carburetor and the laminated filtermeans for removing gasoline from the fluid flowing through the valve.